Example NGINX configuration using auth_request and auth_request_set directives to route users

nginx.conf

user  nginx;
worker_processes  auto;
error_log  /var/log/nginx/error.log info;
pid        /var/run/nginx.pid;
events { worker_connections  1024; }

http {
	default_type  text/html;
	log_format  main  '$remote_addr -> $request	$status $body_bytes_sent bytes -> $upstream_addr';
	access_log  /var/log/nginx/access.log  main;

	map $dynamic $upstream {
		pilot		pilot;
		normal		normal;
		default		default;
	}

	upstream pilot {
		zone pilot 64k;
		server 127.0.0.1:4001;
	}

	upstream normal {
		zone normal 64k;
		server 127.0.0.1:5001;
	}

	upstream default {
		zone default 64k;
		server 127.0.0.1:6001;
	}

	upstream auth {
		zone auth 64k;
		server 127.0.0.1:3001;
	}

	server {
		status_zone auth-backend;
		listen 3001;
		location / {
			#return 403;
			return 200 "User is authorized.\n";
			#add_header X-Route "normal" always;
		}
	}

	server {
		status_zone pilot-backend;
		listen 4001;
		location / {
			return 200 "This request has been accessed by a Pilot User. - X-Route: $http_x_route \n";
		}

	}

	server {
		status_zone normal-backend;
		listen 5001;
		location / {
			return 200 "This request has been accessed by a Normal User. - X-Route: $http_x_route \n";
		}
	}

	server {
		status_zone default;
		listen 6001;
		location / {
			return 200 "This request has no X-Route header specified on the backend. - X-Route: $http_x_route \n";
		}

	}

	server {
		status_zone nginx-frontend;
		listen 80;
		location / {
			auth_request /auth;
			auth_request_set $dynamic $upstream_http_x_route;
			proxy_set_header X-Route $dynamic;
			proxy_pass http://$upstream;
		}

		location /auth {
			proxy_pass http://auth;
			proxy_pass_request_body off;
			proxy_set_header Content-Length "";
			proxy_set_header X-Original-URI $request_uri;
		}

	}

	server {
		listen 8080;
		status_zone status-page;
		root /usr/share/nginx/html;
		location = /status.html { }
		location = /status-old.html { }
		location = / {
			return 301 /status.html;
		}
		location /status {
			status;
			status_format json;
			access_log off;
		}
		location /upstream_conf {
			upstream_conf;
		}
	}
}